Furnace unloader



Patented Aug. 14, 1945 UN ITED STATES yPATIENL'Ir OFFICE FURNACE UNLOADER- Fred H. Loftus, Mount' Lebanon; Pa. Application' August, 11, 1943, serial' No. 498,180

7 Claims.

My invention relates. in general to industrial furnace practice; for. example, to furnaces. for heating slabs, billets, ingots, or other metal stock, preparatory to rolling or forging operations, and the invention is particularly directed to apparatus for handling the billets, or other stock, which form the charges of suchfurnaces.

More particularly, the apparatus ofi my invention is designed for unloading heated stock piece by piece from a furnace, and. for convenience in expression, and not by way of limitation, Iherein call the apparatus a furnace unloader.

The invention consists in certain new and,A useful improvements in apparatus of the sort alluded to, and in the ensuing specification I shall describe the invention in exemplary way, as it has been developed for the unloading of billets, with the understanding that the term billets in the claims shall' be inclusive of other kinds of stock to be unloaded or otherwise handled.

In the accompanying drawings, an apparatus embodying the invention is illustrated:

Fig. I is a view in plan of the apparatus, showing a portion of a billet-heating furnace fragmentarily and in horizontal section;

Fig. II is a View of the apparatus as seen on the plane II-II of Fig. I;

Fig. III.' is a view to a larger scale of the apparatus, the view being partly in end elevation and partly in vertical section, on the plane III- III of Fig. I.

The apparatus ofthe invention is, when inservice, positioned before the door of a furnace in which billets are heated. In this case', the apparatus is permanently mounted on two spaced basal members or pedestals 2 and 3 before. the discharge door 4' of a continuous. heating furnace 5, upon the hearth 6 of which a succession oil billets B-A is advanced and heated in known way. Extending from the sill of the door is. a billet receiver. This receivermay be in the form of a billeteconveying table, a known piece of equipment for trans'- porting the billets removed'fromY theA furnace to a rolling mill, forge press, or to another conveyor for handling the. billets in desired manner. The conveyor table consists in a line of rollers'that may be powerfully rotated to effect the advance of billets delivered theretoV from the furnace, or' the line of rollers may be inclined downwardly from the door ofthe furnace, so that gravity will effect the travel of the billets'. Again, the billet-receiver may consist in a skidway of known sort. However, the particular form of the conveyor is not ofthe essence of my invention, and herein I have diagrammatically indicated in" dotted lines, (Fig. Il),

therollersl ofia conveyor of tle type first' mentioned. The pedestals 2 and" 3 are arranged on opposite sides. of the conveyor, and' on suchpedestals, means are supported for pullingthe billets Bfrom the furnace one by one.

SuchV means comprise an elongatearm 8 on whose proximate end-proximate with 'respect to the furnace 8'-a bi1letengaging device" 9 is carried. The arm.8 is of' I shape in cross section; the. arm. ismounted.- for longitudinal or axial re'- ciprocation upon two pairs of rollers III that'ensage thev I shaped body of the arm, as shown in Fig..-III. The two pairs' of rollers I II' arerjournaled inahousing II. The housing II" is mounted; for rocking movement upon a shaft I2",.whi'ch is jour'- naled in bearings 2Il` and 30 on the two 'pedestal members.k The housing II Aincludes two` bearings IIIJ. that provide the essential rotatable engage'.- mentbetween the housing and shaft.

A gear-motor I3, mounted` upon the pedestal 3i`s connected by means. of" coupling Il to. the shaft; I2, andfmeans are provided within the housing III, for moving the arm 8' longitudinallyin one direction ory the. other, accordingV as' the. shaft I2 is rotated in oneA direction or the other.'` Such means comprise a gear-wheel.l I5 secured to the shaft I2" and meshing with a toothed rack I6 united to or integralwith the' upper faceY of the The energizing of the motor I3in one direction of rotation or the -other is controlled by means'of a start-stop reversing switch IT of" conventional construction.

In orderto.-unload' or remove a. heated billet from the furnace, thje. motor'f3 isenergized. to drive the shaftV IZ in. counterclockwise direction (Fig. ID., with the effect that thearm 8 is moved in left-to-right direction; The proximate end" ofthe arm isproject'edthrough the door andi'nt'o the furnace,.andlunder theweight ofthe so`proiected endfi'the arm,` the^ housing II` and arm tend to turn. clockwise. However, the billeteengagng de"- vice Sinclud'es a"semi-sphericalportion, oruother olwious'device,A 915V which bears upon and rides the surface of thebill'et B1 which istoberemoved fromthe furnace.; yAs soon asy the proximate' end ofthe arm treaclres azndpasses the remote lcn'd of the billet B1; the arm tilts into'the position indicated inbreken linesi'n Fig.' II, and" the V*shoulder portion su of thebillet-engaging `device takes purchase upon the remote end of' thez billet. It will be perceived that thehousingl IF, by virtue of its pivotal'support'on shaft I2, rocks infclockwise directi'onand`V permits theuarm''` to tilt und'erthe influence ofvvv gravity as' described; VAnd it will further be noted that the direction of rotation of the shaft I2 in the bearings III) of the rocking housing or support I I is such that the friction between the rotating shaft and the bearings tends to oppose the rocking and tilting movements described, and thus provides for smoother operation of the apparatus.

When the billet B1 has been engaged by the device `Il, the direction of rotation of motor I3 is reversed. Inconsequence, the arm 8 Vis moved in right-to-lefty direction, (Figs. I and II) sliding the billet Bll from the floor of the furnace into position upon the conveyor 1. As the billet approaches and enters delivered position upon the conveyor,

the outer or distal end of the arm 8 reaches such position to the left of the rocking support or housing I l that gravity is effective to tilt the arm and rock the housing in counterclockwise direction, whereby the proximate end of the arm rises and disengages the device 9 from the end of the billet, if indeed such disengagement has not already Abeen effected by the action of the conveyor in moving the billet away from the furnace.

The switch I1 is operated to stop the motor I3, with the proximate end of the arm 8 in 'elevated position, ready again to be projected into the Afurnace for the removal-of a billet,it being understood that the line `of billets isvadvanced overy the hearth of the furnace, stepby step vand in such manner that the billets are brought successively to position opposite the'discharge door 4.

Whenthearm 8 is moved through its -billet- 'withdrawing' stroke, the friction between the rotating shaft I2 and the' bearings I I0 of the housing II, acts to oppose the counterclockwise rocking movement of the housing I I (Fig. II) andthe tilting of the arm 8 into billet-disengaging position'g'As already mentioned, the effect 'of rotational friction in opposing the tilting of the arm `8` tends to eliminate violent movement ofthe arm as it enters unbalanced position. In further providingfor the elimination of racking strains in the apparatus, I organize with vhousing II means for yieldingly limiting the angular or ,tilting movenient of the arm. Such means comprise compression' springs I8, arranged one on each sideof the center I2 onwhich the housing II and arm 8 tilt. Each spring is secured between'a ledge I8 on the bearing block 20 and a lug 2| integral with the housing II, cf. FigsI and Il'I.V The'effectof thesespringsis to cushion the'` movements ofthe arm 8.

Sometimes it may be desirable to adjust the arm 8 laterally of its extent, so'thatjitfmay'be 'brought into centered position with respect 'to the billet B1 in the furnace which is to be unloaded' or removed. In order to afford such vadjustment, I mount the pedestal'3 for sliding movement on 'a bed 3l, and mount the bearing 20 in like manner on the pedestal 2. The pedestal 3 carries `a toothed rack 22 (Fig- III), 'with which meshes 4a` gear-wheel 23, secured toa shaft 24 that is connected to a gear-motor 25 (Fig. 1) con'- trolled through a start-stop reversing'switch' `o`r ing the parts while leaving the housing II free for rocking or tilting movement. In this case, such means comprise keeper blocks 21 secured to flanges 28 on the housing II, and severally embracing the peripheries of circular flanges 29 that are concentric with the shaft I2 and integral with the bearings 20 and 30 provided respectively on the pedestals or support members 2 and 3. The engagement of the blocks 21 with the flanges 28 unites the housing I I with supporting bearings 20 and 30 for common adjustment laterally' of the arm 8, without interfering with the rocking move- -fment of the housing I I on the axis of the shaft I2.

be shifted on the bed 3|', either tothe right or to the left, as desired. The slidably mounted bearing 20 and the housing I I and arm Bare'arranged to move in unison with the pedestal 3, so. that the said movement of thepede'stal 3 effects the desired laterallyl adjustment ofthe arm..v Various means may be provided for so interconnecttions, refinements and elaborations are permissible.

I claim as my invention: 1. Apparatus for removing billets from a furnace comprising a housing with two aligned laterally extending bearings, means for tiltably supporting said housing comprising a shaft extending through said bearings, an arm mounted in 4said housing below said shaft for longitudinal movement, means carried by the furnace-entering end of said arm for engaging a billet, the

weight of the' furnace-entering end of said arm effecting, as the end of the arm is advanced into the furnace, a tilting of said housing and arm, whereby a billet in the funrace may be engaged by said billet-engaging means, means for moving said arm into and out of the furnace including a toothed rack on said arm, a pinion on said shaft in 'meshwith said rack, and means provided for rotating said shaft in reverse directions whereby the friction between the shaft and said bearings opposes the tilting of said housing and arm.

2. Apparatus for removing billets from a furnace comprising ajhousing with two aligned laterally extending bearings, means for tiltably supporting said housing comprising a shaft extending through said bearings, an arm mounted in said housing 'for longitudinal movement, means carried by the furnace entering end of said arm for engaging a billet, the weight'of the furnaceentering .end of ,said arm effecting, as the end of the arm is 'advanced into the furnace, a tilting of said housing and afm, wherebya billet in the furnace may be engaged by said billet-engaging means, means forrnoving said arm into and out of the furnace including a toothed rack on said arm, a pinion on said shaft in mesh with said rack, means providedfor rotating said shaft in reverse directions whereby the friction between the shaft and said bearings opposes the tilting of said housing andarrn, and means positioned between said housing and supporting means for inhibiting, in conjunction with said friction, the violent tilting of said housing and arm.

3. Apparatus for removing Vbillets `from a furnace to a billet receiver comprising two supporting members standing in straddling relation with respect `tosaidA receiver, a rocking support, an -arm mounted in said support for longitudinal movemena means carried by the furnace-entering end of said arm for riding the surface of and engaging the endof .a' billet, mechanism for moving said arm and projecting said end thereof into the furnace, the Weight of the projecting end of said arm effecting,- as the arm advances into the furnace,'a. rocking of said support and tilting of said arm, whereby. said means descend into position to. bear upon and engage a billet in the furnace, and means for reversing said mechanism to reverse the movement of said arm and withdraw the engaged billet from the furnace, the weight of the outer end of said arm effecting, as the billet approaches Withdrawn position, a rocking of said support `and a tilting of said arm in opposite direction, whereby the billet is disengaged.

4. Apparatus for removing billets from a furnace to a billet receiver comprising two supporting members standing in straddling relation with respect to said receiver, a rocking support, an arm mounted in said support for longitudinal movement, means carried by the furnace-entering end of said arm for riding the surface of and engaging the end of a billet, mechanism for moving said arm and projecting said end thereof into the furnace, the weight of the projecting end of said arm effecting, aS the arm advances into the furnace, a rocking of said support and a tilting of said arm, whereby said means descend into position to bear upon and engage a billet in the furnace, means for reversing said mechanism to reverse the movement of said arm and to Withdraw the engaged billet from the furnace, the weight of the outer end of said arm effecting, as the billet approaches withdrawn position, a rocking of said Support and a tilting of said arm in opposite direction, whereby the billet is disengaged, and means cooperating with said rocking support to cushion the movement of said support and arm as they tilt in either `direction.

5. Apparatus for removing billets from a furnace to a billet receiver comprising two supporting members standing in straddling relation with respect to said receiver, an arm mounted between said supporting members for reciprocation and tilting movements, billet-engaging means on said arm, means for reciprocating said arm and causing it to tilt under gravity between billetengaging and billet-disengaging positions, and means for adjusting said arm on said supporting members transversely of the extent of the arm without interference with the capacity of the arm to tilt.

6. Apparatus for removing billets from a furnace to a billet receiver comprising two supporting members standing in straddling relation with respect to said receiver, a support mounted between said members for rocking movement, an arm mounted in said support for longitudinal movement, billet-engagement means on said arm, means for reciprocating said arm in said support and causing the arm and support to tilt under gravity between billet-engaging and billet-disengaging positions, and means for adjusting said rocking support on said supporting members transversely of the direction of the extent of the arm.

7. Apparatus for removing billets from a furnace to a billet receiver comprising two supporting members arranged in straddling relation with respect to said receiver, a bearing member movably borne on each of said supporting members, a support mounted between said bearing members for rocking movement, an arm mounted in said support for longitudinal movement, billet-engaging means on said arm, means for uniting said bearing members and said rocking support for movement in unison in a direction extending transversely of said arm While leaving the arm free for rocking movement with said support, and means for effecting said movement of the so united support and bearing members.

FRED H. LOFTUS. 

